Virtual Hydrilla Field Day 2009

Element 2: Evaluation of currently registered herbicides

As coordinator of Element 2, Dr. Netherland evaluates currently registered herbicides for control of hydrilla and hygrophila. Of the nine active ingredients
currently registered for aquatic use, only four of these compounds (fluridone, endothall, diquat, copper) have been proven effective for hydrilla control. The
products that form the backbone of most state-funded hydrilla control programs include fluridone and endothall.

Due to the limited number of registered products, work on hydrilla control is focused in the following areas:

Evaluations of endothall in high flow areas of the Kissimmee Chain of Lakes or in other Osceola County Lakes where drip applications can be evaluated.

Evaluations of endothall use in the fall and winter for control of hydrilla.

Evaluations of endothall in shallow-water environments, with an emphasis on initial efficacy and longevity of control.

The proposed projects include initial laboratory (replicated trials inside) or mesocosm (replicated trials outside) validation work, followed by
field-scale demonstrations using the most promising techniques.